1. Field of the Invention
This invention relates to methods of testing for honeycomb joining pin seating failures. More particularly it refers to a method of inserting a test pin into an epoxy adhesive to determine if a joining pin has been properly seated in a honeycomb panel.
2. Description of the Prior Art
U.S. Pat. No. 4,370,372 describes a pin for joining two composite honeycomb panels and a method for joining the honeycomb panels using the pin. The pin described in the patent has received widespread commercial acceptance for use in joining honeycomb panels, particularly those panels used in aircraft. The only problem encountered in the use of the pin is occasional improper mixing of the epoxy adhesive anchoring material or poor bonding of the pin. Heretofore, there has been no reliable, inexpensive method of testing for improper bonding. Related, testing procedures for determining adhesive strength of a thin film to a surface are described in U.S. Pat. Nos. 3,336,797 and 3,527,093. A device for measuring tack time is described in U.S. Pat. No. 4,312,212. U.S. Pat. No. 4,538,083 describes a method for testing the tensile strength and bonding strength of sprayed on foam insulation attached to fuel tanks. A reliable and inexpensive method of testing for proper bonding of a pin joining two honeycomb panels is needed.